Apparatus for loading a pull tab on a slider body

ABSTRACT

An apparatus for loading a pull tab on a slider body in a machine for progressively assembling sliders for slide fasteners is disclosed. The machine comprises a base, a turret supported on the base so as to rotate about its center axis and has a plurality of spaced-apart recesses arranged circumferentially around and on the turret for receiving and holding a slider body, a plurality of assembling stations arranged around the periphery of the turret, and means for intermittently rotating the turret so as to position the slider body holding recess successively opposite each of the stations. The apparatus is disposed at one of the assembling stations and comprises a pull tab supply means and a pull tab holding means. The pull tab supply means includes a holder provided on the base, a chute supported by the holder and extending substantially vertically for receiving longitudinally aligned pull tabs therein and directing them toward a pull tab receiving portion in the recess by gravity, and means for discharging pull tabs one by one from the chute. The pull tab holding means is positioned between the outlet of said chute and the pull tab receiving portion of the recess and is movable between an advanced position and a retracted position. The pull tab holding means forms a guide channel for pull tabs discharged from the chute between the outlet of the chute and the pull tab receiving portion of the recess in the advanced position and the guide channel is opened in the retracted position to thereby release the pull tab therefrom.

BACKGROUND OF THE INVENTION

This invention relates to an apparatus for loading a pull tab on aslider body in a machine for progressively assembling sliders for slidefasteners.

Various types of machines for progressively assembling sliders for slidefasteners are known. Typical of such machines is the slider assemblingmachine which includes a base, a turret rotatably supported on the baseand a plurality of spaced-apart recesses arranged circumferentiallyaround and on the turret for receiving and holding a slider body. Aplurality of assembling stations are arranged around the periphery ofthe turret, and means are provided for intermittently rotating theturret so as to position the slider body holding recess successivelyopposite each of the stations. The pull tab loading station is one ofthe assemblying stations of such machine and there the pull tabs areautomatically supplied and attached to the slider body in the turretrecess. One example of a slider assembling machine which includes a pulltab loading station is shown in U.S. Pat. No. 3,138,852. However, in themachine of this U.S. Patent, the pull tab supply chute which guides pulltabs from the hopper to the pull tab loading position is arcuate and thepull tab is supplied horizontally to the loading position. Therefore,the pull tab must be supplied by use of specific supply means which israther complicated and requires a specific drive source. Also, in themachine of the U.S. Patent, a detecting means which detects absence ofthe slider body in the turret recess and stops supply of the pull tab tothe loading position is provided. However, the detecting means of theU.S. Patent uses an electric sensor and stopper. Therefore, thedetecting means is very likely to cause trouble and, also, it needs aspecific electric energy source. Further, in the machine of this type,it is necessary to have the pull tab fall down on the slider body in apredetermined fashion when it is loaded on the same in preparation forthe next working station. Namely, at the next station, the pull tabloaded on the slider body is detected by the sensor and is fixed to theslider body by caulking operation in falled down state.

SUMMARY OF THE INVENTION

Therefore, an object of this invention is to provide an apparatus forloading a pull tab on a slider body which is very simple in constructionand does not need a specific drive source.

Another object of this invention is to provide an apparatus for loadinga pull tab on a slider body whereby the pull tab is supplied to theproper position on the slider body one by one by gravity.

Still another object of this invention is to provide an apparatus forloading a pull tab on a slider body whereby, without trouble and withouta special energy source, the supplying of a pull tab to the loadingposition is positively prevented when there is no slider body in theturret recess.

A further object of this invention is to provide an apparatus forloading a pull tab on a slider body whereby the pull tab positivelyfalls down on the slider body in a predetermined fashion when it isloaded on the same.

The present invention may be summarized as an apparatus for loading apull tab on a slider body in a machine for progressively assemblingsliders for slide fasteners; the machine comprises a base, a turretsupported on the base so as to rotate about its center axis and having aplurality of spaced-apart recesses arranged circumferentially around andon said turret for receiving and holding a slider body, a plurality ofassembling stations arranged around the periphery of the turret, andmeans for intermittently rotating the turret so as to position theslider body holding recess successively opposite each of the stations;the apparatus being at one of the assembling stations, and comprising apull tab supply means and a pull tab holding means; the pull tab supplymeans includes a holder provided on the base, a chute supported by theholder and extending substantially vertically for receivinglongitudinally aligned pull tabs therein and directing them toward apull tab receiving portion in the recess by gravity, and means fordischarging pull tabs one by one from the chute; the pull tab holdingmeans being positioned between the outlet of the chute and the pull tabreceiving portion of the recess and being movable between advancedposition and a retracted position, the pull tab holding means forms aguide channel for pull tabs discharged from the chute between the outletof the chute and the pull tab receiving portion of the recess in theadvanced position and the guide channel is opened in the retractedposition to thereby release the pull tab therefrom.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of one preferred embodiment of the invention;

FIG. 2 is a side view of the apparatus shown in FIG. 1 with severalportions broken away; and

FIG. 3 is a sectional view taken along line III--III of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, one preferred embodiment of this invention will beexplained with reference to the drawings.

FIG. 1 shows a pull tab loading station of a machine for progressivelyassembling sliders for slide fasteners. The machine includes a turret 1which is rotatably supported on a base 6. The turret 1 includes on itsperiphery a plurality of evenly spaced-apart recesses A, B,--forreceiving a slider body 2 therein. A plurality of assembling and orworking stations, which are not shown except for the pull tab loadingstation, are spaced and arranged around the periphery of the turret 1.The turret 1 is intermittently rotated about its central axis by a drivemeans not shown to thereby position the slider body holding recesssuccessively opposite each of the stations. By this, the slider body 2in the recess is subjected to the successive assembling and/or working.In each station, the assembling and/or working operation is startedand/or effected by the up and down movement of a central shaft 3 of theturret 1. In the state of FIG. 1, the slider body 2 in the recess B ispositioned at the pull tab loading station.

As shown in FIG. 2, in this pull tab loading station, a pull tab holder5 is provided on the post 6' which is fixed on the base 6 so that theholder 5 is substantially positioned above the recess B. A chute 8 whichextends substantially vertically is supported by the holder 5. The chute8 includes a groove 8' which receives longitudinally aligned pull tabs4, 7--from the parts feeder (not shown) therein, which parts feeder ispositioned above the chute 8. A lower end outlet 9 of the groove 8' isdirected toward a pull tab receiving portion 10 of the recess B. Betweenthe outlet 9 of the chute 8 and the pull tab receiving portion 10, thereis disposed a pull tab holding means 11, which will be referred tohereinafter in detail.

In order to discharge the pull tabs from the groove 8' of the chute 8one by one, the chute 8 includes a first pin 12, a second pin 13 and athird pin 14 all of which can extend into the groove 8'. The first pin12 extend through the chute 8 into the groove 8' from the backsidethereof so that its forward end can be engaged in the attaching hole 4aof the lower most pull tab 4. The second pin 13 extends through thechute 8 into the groove 8' from the front side thereof so that itsforward end can engage the lower end 15 of the lowermost pull tab 4. Andthe third pin 14 extends through the chute 8 into the groove 8' from thefront side thereof so that its forward end can be engaged in theattaching hole 7a of the next above adjacent pull tab 7.

The first pin 12 is resiliently attached to an upper arm 19 of a C-frame18 through a spring 20, and the frame 18 is fixed to a sliding body 17which is slidably received within a channel 16 formed in the base 6. Thesliding body 17 is normally urged toward the recess B by means of thespring 24.

The frame 18 also includes a lower arm 21. This lower arm 21 is providedwith a detector 22 which extends toward the recess B in the turret 1.The arcuate leading edge 23 of the detector 22, in its projectingposition, projects into the moving pass of the slider body 2 in therecess B, which movement is caused by rotation of the turret 1.Therefore, when the arcuate leading edge 23 is positioned in itsprojecting position and the turret 1 is rotated so that the recess Bcome to the pull tab loading station, the slider body 2 in the recess Bcontacts the arcuate leading edge 23 and pushes the lower arm 21 and theframe 18 in the direction of the arrow in FIG. 2. By this, the first pin12 is retracted so as to be disengaged from the lowermost pull tab 4.

When the arcuate leading edge 23 and the slider body 2 becomesdisengaged, the sliding body 17 is pushed toward the recess B by theaction of the spring 24. By this, the first pin 12 returns to itsoriginal position where it engages the lowermost pull tab. Of course,the arcuate leading end 23 of the detector 22 returns to its extendedposition where it projects within the moving path of the slider body.

When, by the rotation of the turret 1, a recess B which does not hold aslider body 2 therein comes to the pull tab loading station, the arcuateleading edge 23 of the detector is not deviated from its projectedposition, and thus the first pin 12 is not retracted from its extendedposition. Therefore, the supplying of a pull tab from the groove 8' isprevented.

On the other hand, the second pin 13 and the third pin 14 are fixed onthe opposite ends 26, 27 of a rocking arm 25, and this rocking arm 25 isswingably supported at its intermediate portion to the chute 8 by meansof the pin 28. One end of the rocking arm 25 is pulled by a spring 29,which is connected between one end 26 of the arm 25 and the chute 8, sothat the second pin 13 normally engages the lower end 15 of thelowermost pull tab 4. By this pulling action of the spring 29, the thirdpin 14 fixed on the other end 27 of the rocking arm 25 is urged to itsnormal position where the forward end of the third pin does not engagethe next pull tab 7 adjacent the lowermost pull tab 4.

A rotatable cam follower 30 is pivoted at the end 27 of the rocking arm25 on the opposite side of the third pin 14. On the other hand, a cam 31is fixed to the up and down movable shaft 3. The cam follower 30 ispositioned within the path of the up and down movement of the projectingportion 32 of the cam 31.

Therefore, when the shaft 3 is lowered after a recess B is positioned atthe pull tab loading station, the cam follower 30 is pushed by thelowering cam projection 32. By this, the rocking arm 25 is rotated inthe direction of the arrow against the resilient force of the spring 29,and thereby the third pin 14 is brought to engage in the attaching hole7a of the pull tab 7 and the second pin 13 is brought to disengage fromthe lower end 15 of the lowermost pull tab 4. To the contrary, when theshaft 3 is moved upwardly, the cam projection 32 disengage from the camfollower and the rocking arm 25 is returned to the position in FIG. 2 bythe action of the spring 29.

The space L which is greater than the length 1 of the pull tab isprovided between the outlet 9 of the chute 8 and the pull tab receivingportion 10 of the recess B, and the aforementioned pull tab holdingmeans 11 is disposed within this space L. The pull tab holding means 11includes a pair of laterally disposed clamping members 33, 34.

These clamping members 33, 34 include on their opposed inside walls 35,36 (only 35 is shown) slots 37, 38 respectively. These slots 37, 38define a pull tab guide channel connecting between the outlet 9 of thechute 8 and the pull tab receiving portion 10.

These clamping members 33, 34 include arms 39, 40 respectively. Thesearms extend in parallel to the direction in which the pull tab 4'supplied to the slider body 2 is falled down as hereinafter explained.These arms 39, 40 are pivoted to a sliding member 44 by means of asingle shaft 43 at their intermediate positions between the clampingmembers 33, 34 and end portions 41, 42 thereof.

The sliding member 44 is slidably mounted within a channel in a machinebase and is connected to an up and down movable rod 48 through a link 46and a bell crank 47. The bell crank 47 is pivoted to the base. When therod 48 is moved downwardly and upwardly, the sliding member 44 isretracted in the direction of the arrow (FIG. 2) and advanced in theopposite direction respectively. This up and down movement of the rod 48is effected by a drive means not shown.

On opposite sides of this sliding member 44, a pair of fixed cams 49, 50is fixed on the machine base 6.

On the rear end portions 41, 42 of each of the arms 39, 40, rollers 51,52 are pivoted respectively. A spring 53 is compressed between the endportions 41 and 42 so that it resiliently pushes the end portionsoutwardly. By this, the rollers 51, 52 are resiliently urged to the camsurfaces of the fixed cams 49, 50.

These fixed cams 49, 50 include first parallel cam surfaces 54, 55 onthe forward side thereof and second parallel cam surfaces 56, 57 on therearward side thereof. The space between the first cam surfaces 54, 55is wider than that of the second cam surfaces 56, 57. The space betweenthe first cam surfaces 54, 55 is so selected that the guide channelwhich smoothly guides the opposite sides of the pull tab is formed bythe slots 37, 38 of the clamping members 33, 34 when the rollers 51, 52are in contact with the cam surfaces 54, 55. The space between thesecond cam surfaces 56, 57 is so selected that the end portions 41, 42are closed to each other, thus the clamping members 33, 34 are separatedfrom each other and the space between the slots 37, 38 of the clampingmembers is opened wider than the width of the pull tab when the rollers51, 52 are in contact with the second cam surfaces 56, 57. The fixedcams 49, 50 include tapered surfaces 58, 59 which allow excess openingof the clamping members 33, 34.

The operation of the apparatus is as follows. Before starting of theloading operation, the pull tabs 4, 7--are received within the channel8' as shown in FIGS. 2 and 3, the first pin 12 and the second pin 13 areengaged in the hole 4a and bottom end 15 of the lowermost pull tab 4respectively, and the third pin 14 is positioned at disengaging positionagainst the next adjacent pull tab 7. In this position, the arcuateforward end 23 of the detector 22 projects within the moving path of theslider body 2 in the recess B.

With such arrangement, when the recess B is rotated by the rotation ofthe turret 1 and comes to the position of FIG. 1, the rotation of theturret 1 is stopped and the detector 22 is rertracted against the forceof the spring 24 by the engagement between the arcuate forward end 23 ofthe detector 22 and the slider body 2 received in the recess B. By this,the first pin 12 is retracted to the disengaging position.

However, if there is no slider body 2 within the recess B, as thearcuate forward end 23 of the detector 22 is not engaged by the sliderbody 2, the fist pin 12 is retained in its engaging position, and thusthe supplying of a pull tab from the chute 8 is prevented despite thefurther operation of the other portions.

In response to the stop of the turret rotation, the shaft 3 is loweredand thus the cam follower 30 is pushed by the cam projection 32 of thecam 31. By this, the rocking arm 25 is rotated in the direction of thearrow in FIG. 2, and the second pin 13 is disengaged from the lower end15 of the lowermost pull tab 4; at the same time the third pin 14engages the above next adjacent pull tab 7. Therefore, the lowermostpull tab 4 is slid down toward the pull tab receiving portion 10 of therecess B and is positioned at 4' as shown in FIG. 3. However, the aboveadjacent pull tab 7 is retained in its position by the third pin 14.After this, the shaft 3 is moved upwardly and the engagement between thecam projection 32 and the cam follower 30 is broken. By this, therocking arm 25 is returned to its original position by the spring 29,and thus, the third pin 14 is returned to the disengaging position andthe second pin 13 is returned to the engaging position. Therefore, theabove adjacent pull tab 7 is slid down and its lower end is engaged bythe second pin 13 in preparation for the next cycle.

When the pull tab 4 is slid down in the position 4' of FIG. 3, theforward end of this pull tab 4' reaches the pull tab receiving portion10 of the recess B and both side edges of the pull tab 4' are receivedwithin the slots 37, 38 of the clamping members 33, 34. At this time,the rod 48 is lowered by the operation of interlocking mechanism (notshown), whereby the sliding member 44 is initiated to retract in thedirection of the arrow in FIG. 2.

When the sliding member 44 is retracted, the rollers 51, 52 of the arms39, 40 are first guided by the widely spaced first parallel cam surfaces54, 55 and the space between the slots 37, 38 of the clamping members33, 34 is not changed. By this, the pull tab 4' is held and moved by theslots 37, 38 of the clamping members 33, 34 in the direction of thearrow, and the lower attaching hole 4a of the pull tab 4' is fitted overthe lug 2a of the slider body 2 through the receiving opening 2b of thelug 2a. When the sliding member 44, i.e., the clamping member 33, 34, isfurther retracted in the direction of the arrow, the rollers 51, 52 areguided by the narrower second parallel cam surfaces 56, 57. By this, thespace between the slots 37, 38 of the clamping members 33, 34 is openedwider than the width of the pull tab 4', and therefore, the pull tab 4'is released from holding by the clamping members 33, 34. As the releaseof this holding is effected during the retracting movement of theclamping members 33, 34 in the direction of the arrow, the pull tab 4'falls down on the slider body 2 in the direction of the arrow when it isreleased from the holding.

After this, the rod 48 is moved upwardly whereby the clamping members33, 34 are returned to their original position as shown in FIGS. 1 and 2in preparation for the next cycle.

After completion of this returning of the clamping members 33, 34 totheir original position, the turret 1 is rotated. When the turret 1 isrotated, the arcuate forward end 23 of the detector 22 is disengagedfrom the slider body 2 in the recess B and returns to its projectedposition. Therefore, the first pin 12 again engages the hole 4a of thelowermost pull tab.

Although, in the above stated embodiment, the first pin 12 and third pin14 are engaged in the holes 4a, 7a provided in the end portion of thepull tabs to hold them in position, the engagement of pins in the holes4a, 7a is not always necessary. Alternatively, the pull tabs can be heldin position by pushing the surfaces thereof by the pins 12, 14. Also, inthe above stated embodiment, although the pull tab 4' is loaded on theslider body 2 by fitting the attaching hole 4a of the pull tab over thelug 2a of the slider body 2, such fitting of the hole over the lug isnot always necessary for attaching the pull tab to the slider body. Thepull tab may be loaded on the slider body by supplying it to the pulltab receiving portion of the recess and thereafter directly falling downon the slider body. In such a case, the fixed cams 49, 50 of FIG. 1 arereplaced by ones which include the second parallel cam surfaces 56, 57on the forward side of the fixed cams and the pull tab, which isreceived in the pull tab receiving portion 10 of the recess B, may bedropped directly onto the slider body by just moving and opening theclamping members 33, 34.

Thus, in accordance with the present invention, since the supply of thepull tabs to the slider body is effected by using gravity on the pulltabs and up and down movement of the shaft of the machine, no specificdrive means and drive source is necessary. Also, since one by one supplyof the pull tab to the slider body is effected by use of simple pins,rocking arm, cam and cam follower, the construction of the apparatus isvery simple. Moreover, since the detector is mechanically operated byuse of turret rotation, few trouble occurs and no specific energy sourceis needed to the detecting operation. Further, since the pull tab isdropped on to the slider body by use of the pull tab holding means, thepull tab always falls down on the slider body in the proper position.

What is claimed is:
 1. An apparatus for loading a pull tab on a sliderbody in a machine for progressively assembling sliders for slidefasteners, said machine comprising a base, a turret supported on thebase for intermittent rotation about its center axis and having aplurality of spaced-apart recesses arranged circumferentially around andon said turret for receiving and holding a slider body, a plurality ofassembling stations arranged around the periphery of said turret, andmeans for intermittently rotating said turret so as to position a sliderbody holding recess successively opposite each of the stations, saidapparatus being at one assembling station of said assembling stationsand comprising a pull tab supply means and a pull tab holding means;said pull tab supply means includes a holder provided on the base, achute supported by said holder and extending substantially verticallyfor receiving longitudinally aligned pull tabs therein and directingthem toward a pull tab receiving portion in said recess by gravity, andmeans for discharging pull tabs one by one from the chute; said pull tabholding means is positioned between an outlet of said chute and the pulltab receiving portion of said recess and is movable between an advancedposition and a retracted position; said pull tab holding means beingarranged to form a guide channel for receiving a pull tab dischargedfrom the chute between said outlet of said chute and the pull tabreceiving portion of said recess in said advanced position, and meansfor opening the guide channel in said retracted position to therebyrelease a pull tab therefrom to drop said tab into said pull tabreceiving portion of said turret recess.
 2. An apparatus for loading apull tab on a slider body as defined in claim 1 wherein said means fordischarging pull tab one by one from the chute comprises a detectingmeans slidably mounted on said base between a projected position and aretracted position, a forward end of said detecting means being withinthe path of rotational movement of said slider body received within saidrecess upon rotation of said turret in said projected position; a springmeans for urging said detecting means toward the projected position; afirst pin fixed to said detecting means and being projectable into saidchute, said first pin engaging and disengaging the lowermost pull tab inthe chute when said detecting means is in its projected position andretracted position respectively; a rocking arm swingably mounted at anintermediate portion thereof to said chute and having a second pin andthird pin on a lower end portion and an upper end portion respectively,said second and third pins being projectable into said chute, saidrocking arm being swingable between a first position wherein said secondpin and third pin engages and disengages a lower end of said lowermostpull tab and a next above adjacent pull tab respectively, and a secondposition wherein said second pin and third pin disengage and engage saidlower end of said lowermost pull tab and said next above adjacent pulltab respectively; a spring means normally urging said rocking arm intosaid first position; a cam provided on said turret; and a cam followermounted on said rocking arm and being engageable with said cam, meansmoving said cam downwardly upon intermittent stopping of the turret tothereby move said rocking arm into said second position thereof.
 3. Anapparatus for loading a pull tab on a slider body as defined in claim 1wherein said pull tab holding means comprises a sliding member slidablymounted on said base between said advanced position and said retractedposition; a pair of opposed clamping members having forward and rear endportions, said members being pivoted at intermediate portions thereof tosaid sliding member; a pair of fixed cams positioned on opposite sidesof said clamping members, each forward end portion of said clampingmembers having a slot for forming said guide channel between clampingmembers, each rear end portion of said clamping members having a rollerfor contacting the opposed fixed cam; a spring means provided betweensaid clamping members for urging said rollers against the fixed cams;said fixed cams including first cam surfaces on forward sides thereofwhich cause the clamping members to form said guide channel and secondcam surfaces on rearward sides thereof which cause the clamping membersto open said guide channel wider than the width of the pull tab; andmeans for moving said sliding members between said first and secondpositions.